|Home | About | Journals | Submit | Contact Us | Français|
According to the U.S. Centers for Disease Control (CDC) Report on Epilepsy Surveillance among Adults, it is estimated that 61.5% of American adults with a history of epilepsy report having had more than one seizure in the month prior to the survey.1 Thirty-five percent reported not having seen a neurologist or an epilepsy specialist.1 Moreover, individuals with epilepsy were likely to report poorer health, had higher rates of unemployment, and have had significantly worse health-related quality-of-life than individuals with other chronic medical conditions. Despite neuroscience advances providing a better understanding of the spectrum of epilepsy morbidity and mortality, and a plethora of therapeutic options, it appears that limited progress has been made on the overall well-being of the patient with epilepsy.
This year's annual course at the American Epilepsy Society meeting in Baltimore, MD, delved into obstacles that preclude successful epilepsy management. Three broad categories of barriers were explored:
The goal of the course was not to simply itemize barriers but to provide insightful practical ways in which individuals that care for or research the issue of epilepsy can help to overcome these barriers. Through a series of didactic lectures, panel discussions, debates, and question and answer sessions (all framed with illustrative case presentations), the course illuminated a path where successful treatment may be able to occur.
Classification of the epilepsies and seizures can be a force for positive change; however, it can also present as a barrier to meaningful clinical conversation. The focus with any given individual patient should be on an accurate diagnosis. The paroxysmal presentation of epileptic seizures and the lack of a reliable interictal biomarker present a barrier in diagnosing and monitoring epilepsy. Techniques to overcome this obstacle involve obtaining appropriate genetic, clinical history, video-EEG, and imaging studies. It is essential to know the common diagnostic guidelines for solidifying a specific epilepsy diagnosis in order to best help the patient.
Advances in genetics have helped to identify where genes are obstacles to successful management. Copy number variations and de novo mutations are misunderstood, and estimates of their prevalence are low. One area of epilepsy genetics that has translated to clinical use is pharmacogenetics. The findings of the HLA haplotypes that predict certain individuals may be at risk for a serious rash associated with carbamazepine exposure is a quantum leap and serves as a glimpse on how genetic tests may be useful in tailoring individual agents to the patient.
Because a seizure diagnosis requires recording an actual seizure on EEG, this diagnostic tool can obstruct a diagnosis. Interictal discharges can falsely localize, and while the irritative and ictal onset zones may provide an estimate of the epileptogenic zone, they may not be congruent. An EEG should always be interpreted within its clinical context with full knowledge of the limitations of EEG data. Moreover, there are a number of benign variants often mistakenly diagnosed as being epileptiform and leading to a cascade of inappropriate therapeutic choices. Thus, competently identifying benign EEG variants is essential to successful epilepsy care.
With regards to imaging, it is essential to always formulate a question that imaging will help to answer. Imaging, in and of itself, should not be the sole reason that it is obtained; there must first be a clear hypothesis about the expectation of the results. One has to consider etiologies and localization. There is a wide variety of imaging procedures available to evaluate patients with epilepsy, including CT, many choices of MRI, PET with a variety of ligands, and SPECT. In addition to choosing studies designed to answer specific clinical questions, it is important to have a good sense of the special features and limitations of each in order to be able to choose the most appropriate procedure and avoid unnecessary tests. For example, PET is poor for identifying underlying pathology but good for defining regions of functional deficit that may extend beyond the “seizure-onset zone.” Imaging results should not be considered in isolation but interpreted in a clinical context. It is important to have adequate control data for comparison; some degree of increased FLAIR signal, for example, may be found in healthy volunteers. Dialogue with a radiologist is paramount.
Some technical issues, such as “partial volume effects,” may be important for interpretation of functional imaging studies. Ictal SPECT interpretation depends crucially on the relation of injection time to seizure onset, as well as the degree of seizure spread. PET may reflect the effects of cognitive dysfunction or mood disorder; depending on the ligand used, activity is averaged over 40 to 90 minutes. Recent seizure activity may influence results. The wide range of MRI sequences available, as well as hardware such as surface coils, makes it important to consult with radiologists to plan studies, particularly when occult lesions such as focal cortical dysplasia are suspected; “routine” MRI may not be helpful. Some new techniques such as DTI and VBM may reflect wider cortical injury as a result of seizures.
fMRI has now arrived as a standard of care for many patients undergoing epilepsy surgery evaluations, yet it has limitations. Results can be affected by large lesions such as tumors or AVMs, possibly a prolonged postictal period after a seizure cluster. It is crucial to understand the neuropsychologic tests used as well as the analytic approach; varying statistical thresholds may produce varying image results. In summary, when it comes to both EEG and imaging, it is important to keep in mind how little we really know about these studies, and we should not rely on any one of these tests in isolation.
Although there are 24 different antiepileptic drugs (AEDs) available for use in the United States, we still have little data to guide us in deciding how to best choose a single agent for a given patient. Moreover, the focus of epilepsy drug treatment is on seizure control and not an epilepsy cure. To improve medical therapy for epilepsy, better animal models that individualize therapies are needed. It is essential to transform AEDs from an anti-seizure aim to an antiepileptogenic goal. We need to also have a combination of randomized clinical controlled trials and pragmatic trials utilizing comparative effectiveness as a way to provide a complete picture of how to use a drug and to identify the best population for a given agent.
Adherence to AED therapy is often the 800-pound gorilla in the examination room and can lead to inaccurate clinical decisions (e.g., changing drug or dose and leading to a misdiagnosis of drug-resistant epilepsy) when patients continue to have seizures. Non-adherence to AED therapy leads to significant morbidity, mortality, and diminished quality of life. Enough emphasis cannot be placed on the importance of developing reliable and validated educational tools and using objective electronic monitors that measure adherence in a clinic setting.
Two central issues continue to serve as barriers to successful epilepsy surgery; long-term efficacy and access to an epilepsy surgery center. Even after 3,801 publications on epilepsy surgery and 60 years after Wilder Penfield described the benefits of epilepsy surgery, the long-term effectiveness rate of this therapy has remained unchanged at 55%. Oftentimes, clinicians fail to grasp the next best approach in the case of seizure recurrence. Re-operation offers the best chance of achieving seizure-freedom and needs to be investigated when epilepsy surgery has failed. Accurate epilepsy localization is critical to prevent epilepsy surgery failure and it is likely that epileptogenesis within networks is the key to late surgical failures. Failure to perform an adequate resection is often the culprit for failure if seizures recur early within the first 6 months. Nevertheless, epileptogenesis is likely the key to late surgical failures, and finding appropriate antiepileptogenic methods may improve long-term seizure outcomes. Small targeted resections such as amygdalohippocampectomy may result in slightly fewer memory deficits, yet there is a potential risk for increased chance of seizure recurrence. One has to balance these two important variables when counseling patients, and studies have to be performed that address the comparative effectiveness of various limited resection techniques.
Even more problematic is the issue of access to an epileptologist who can evaluate a patient for potential surgery. Currently, there is a broader variety of conditions and patient types that lend themselves to surgery for epilepsy. Because of advances in imaging and surgical techniques, small children, older adults, and individuals with cortical dysplasia may benefit from operations that were previously never performed. However, the delay to surgery is getting longer, now over 20 years.2 All patients who have seizures after adequate trials of two AEDs should be referred to an epilepsy center. Early referral provides the best chance of avoiding adverse psychologic and social consequences as well as premature death. Even if they are not surgical candidates, they are likely to benefit from a consultation with an epileptologist.
Psychiatric comorbidities are relatively frequent in people with epilepsy, with depression and anxiety disorders being the most frequent with life time prevalence rates of 30 to 35% in population-based studies . Depression in epilepsy cannot be considered any longer as “a normal reaction” to the obstacles associated with this disorder. It is the expression as well of neurochemical and neurophysiologic disturbances in limbic structures. Depression has a very negative impact on the quality of life of patients with epilepsy, not only when presenting as a major depressive episode (its most severe form), but also as subsyndromic depressive episodes . It is associated with worse response of the seizure disorder to pharmacotherapy and surgical treatment and worse tolerance to AEDs . Of greater concern is the fact that affective disorders increase the risk of completed suicide by 32-fold . Given all of the above, patients with epilepsy need to be screened for depression at the time of initial evaluation, in follow-up visits, and in particular, following changes in medication, epilepsy surgery and during pregnancy and the postpartum. Its treatment should be aimed towards complete remission of symptoms.
There are many public health barriers to successful epilepsy treatment. Sadly, disparities in epilepsy care are at the heart of many public health issues regarding seizures. Consider the following facts: emergency room use is higher in minority patients, there is less follow-up care for the uninsured, surgical rates are lower for minorities, there is a lower rate of antiepileptic drug use and nonadherence, and there are fewer neurologic visits for the uninsured. A third of patients with recent seizures had not seen a neurologist in the past year. There is a 53-day wait list for a new visit with a child neurologist and a 44-day wait list for a return visit.2 Patients on Medicaid have difficulties seeing a neurologist often owing to economic issues related to lack of insurance. This is especially true for pediatric patients. It is not difficult to appreciate the significant problems that need to be addressed in order to provide the best quality care for these individuals.
Driving and stigma round out the other major public health barriers to epilepsy care. The United States has approached driving regulations for the person with epilepsy inconsistently, with highly heterogeneous and often confusing individual state laws. Further investigation is needed to identify the optimal seizure-free interval after a seizure has occurred before an individual with epilepsy is allowed to drive. Aside from driving, stigma is a major concern that represents an overwhelming proportion of the psychosocial burden of epilepsy. Stigma knows no boundaries and occurs across all ethnic, gender, educational, and socioeconomic groups, leading to discrimination. Only by frequent, rapid, repetitive, and effective education and the recognition and reconciliation of institutionalized stigma can we reverse the downward spiral of epilepsy.
Fortunately, the public health barriers to epilepsy are being addressed within a new Institute of Medicine report with specific recommendations on the public health dimensions of epilepsy that were released in April 2012.2 It is only by appreciating the global view of epilepsy, as well as its complex nuances within diagnosis, therapy, management, and public policy, that we can truly begin to surmount the many obstacles we face in order to provide the best care for patients with epilepsy.
Editor's Note: Authors have a Conflict of Interest disclosure which is posted under the Supplemental Materials link.